A touch screen for a mobile communication device may be classified into one of two categories: a pressure sensitive type and a capacitive type. The pressure sensitive type is based on a resistor array that senses a signal resulting from a pressure applied to a surface of a screen. And a capacitive type is based on a capacitor array that senses a signal resulting from an amount of discharge from a charged surface of a screen when the surface of the screen is touched. Recently, the capacitive type, which has high-resolution and good sensitivity, has been widely used.
A hover touch recognition function, which extracts information about a position (i.e., a coordinate) from a finger floated over a screen of a mobile device, has been used in connection with devices having capacitive type touch screens. A technique such as the hover touch requires a high level of sensitivity, and the performance of the hover touch may be seriously degraded due to external noise. Examples of such noises include display noise, three-wave length noise, burst noise, and battery charger noise.